The purpose of this resource is to measure the amounts of nitrogen, phosphorous and potassium in each horizon in a soil profile. Using a NPK test kit, students mix a dry, sieved soil sample into a solution and chemically extract the N, P, and K as nitrate, phosphate, and potassium. The N, P, and K amounts in the sample are determined by comparing the solution to a color chart. Students describe the N, P, K amounts as high, medium, low, or none. These measurements are conducted three times for each horizon.

Intended for grade levels:

Middle (6-8)

High (9-12)

Type of resource:

For the classroom:

Classroom activity

Field activity

Subject:

Agricultural science

Soil science

Technical requirements:

Adobe Acrobat reader

Cost / Copyright:

No cost

For science/educational use consistent with the methodologies of the GLOBE Program.

DLESE Catalog ID:GLOBE-98

Educational standards:

National Science Education Standards (NSES):

5-8:

Unifying concepts and processes:

Change, constancy, and measurement

Form and function

A - Science as inquiry:

Abilities necessary to do scientific inquiry

Understanding about scientific inquiry

F - Science in personal / social perspectives:

Populations, resources, environments

9-12:

Unifying concepts and processes:

Change, constancy, and measurement

Form and function

A - Science as inquiry:

Abilities necessary to do scientific inquiry

Understandings about scientific inquiry

D - Earth and space science:

Geochemical cycles

F - Science in personal / social perspectives:

Environmental quality

Natural resources

National Geography Standards:

Environment and society:

How human actions modify the physical env.

The changes that occur in the meaning, use, distribution, and importance of resources